Conventional methods for image object segmentation include automatic segmentation, manual segmentation and semiautomatic segmentation. As for the automatic segmentation, image objects are automatically segmented according to the variations in luminance of successive images. As for the manual segmentation, a user directly segments each of image frames using image editing tools. And as for semiautomatic segmentation, the first image object is segmented manually and then the rest of image objects are segmented automatically.
However, the performance of the automatic segmentation is varied in a wide range due to threshold values to detect the luminance variations in successive images. And the manual segmentation requires too much of time and cost to segment each frame manually. Further, the conventional semiautomatic segmentation does not use information of previously segmented images in automatic segmentation for the rest of image objects.